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What happened to the drive VFD ?

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phatcreators

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What happened to the drive VFD ?

No output , no display , no DC Bus Voltages

Input diodes are shorted out or burnt open ???

thanks
 

Input fuses are fine i checked both of them ........
 

There is a resistor to limit power capacitors initial current. Check this resistor. The resistor in parallel with relay output. The resistor has low value.the resistor in white colour...
Hope this helps...
 

I have also checked the resistor ...... its also fine

If for any problem the resistor got damaged the drive won't generate the DC Bus Voltages ????? Mailus .......
 

but the resistor is fine then what might be the problem ?
 

There is no DC bus voltage right,
it's obviously input bridge rectifier or track. Are you checked these?..
 

I have checked input diodes but they're not right

because i set the DMM on diode range ....


These 6 set of readings are fine

Red Probe on R with black probe on P or (+) : High or Infinite
Red Probe on S with black probe on P or (+) : High or Infinite
Red Probe on T with black probe on P or (+) : High or Infinite
Red Probe on R with black probe on N or (-) : High or Infinite
Red Probe on S with black probe on N or (-) : High or Infinite
Red Probe on T with black probe on N or (-) : High or Infinite

But these 6 set readings are not fine.

Black Probe on R with Red probe on P or (+) : High or Infinite
Black Probe on S with Red probe on P or (+) : High or Infinite
Black Probe on T with Red probe on P or (+) : High or Infinite
Black Probe on R with Red probe on N or (-) : High or Infinite
Black Probe on S with Red probe on N or (-) : High or Infinite
Black Probe on T with Red probe on N or (-) : High or Infinite


what do you say ? What do you conclude then ?

thanks
 

How is it possible all diodes are open.In case of failure may be one or two diodes will be open or short... specify the model and name of the VFD please....
 

k k....i think it has RFI filter in input...check it
 

What's RFI Filter input ? How to check RFI filter input ?
 

it's nothing a coil with capacitor to avoid radio interferences check input and output cable

- - - Updated - - -

it's nothing a coil with capacitor to avoid radio interferences check input and output cable
 

input : R, S & T
Output : U,V & W

Cables ????

check the continuity with ohmmeter ????
 

the RFI filter in bottom of the pcb.. there is a cable between input terminal and board..so check this cable...
 

check their continuity ?

typically a RFI filter consist of what components so that i could easily figure it out ?
 

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